DNA testing for genealogists

In the last decade or so, genealogists have turned to the study of DNA to help trace their family trees or resolve conflicting (or missing) information. Currently, there are three DNA tests that people most often use for genealogy. Y-DNA tests are only available for males, since the Y-DNA takes us down the surname path from our father’s father’s father and so on. mtDNA tests work for both males and females, as mtDNA travels back from our mother’s mother’s mother. Autosomal DNA tests skip the X and Y chromosomes entirely and rely on the other 22 pairs of autosomes. This last test is not as predictable in that you can't follow a surname or maternal line into the past, but you can learn about your ancestral origins.

Three companies in the United States are well known for their genealogical DNA testing. Founded in 1999, FamilyTreeDNA is known for its surname, lineage, and geographical projects. Started in 2006, 23andme focuses on health-related genetic portraits and ancestry data. AncestryDNA is a relative newcomer to the scene, but as part of Ancestry.com, one of the largest online genealogy companies, it has the potential to grow rapidly because of its large subscriber base and its sponsorship of the popular TV show, Who Do You Think You Are? (TLC network). 

In a recent Weekly Genealogist Survey by the New England Historic Genealogical Society (NEHGS), 50 percent of respondents used FamilyTreeDNA for genealogical DNA testing, while 43 percent used AncestryDNA and 16 percent used 23andme. (The 2,855 people who took the survey could select more than one company.) At the Massachusetts Genealogical Council annual seminar in July 2013, speaker Judy G. Russell, The Legal Genealogist, suggested to me to transfer results from one company to the other two to get the most cousin connections. 

Patience is critical for genealogists who have taken DNA tests. After all, 52 percent of the 4,400 people who took another weekly survey by NEHGS have not had their DNA tested. That makes it difficult to find your closest (unknown) relatives through genetics. But some genealogists have taken more than one DNA test, with 28 percent testing their own or a male relative's Y-DNA; 26 percent testing their own mtDNA; and 25 percent had an autosomal test.

So test yourself, and then ask your relatives and potential cousins to test their DNA too.